JSFiddle - React, Tailwind, and code Playground
HTML
<input type="file" accept="image/*" onchange="validateFileFormat()" multiple id="i" />
JavaScript
window.validateFileFormat = function() {
const valid = [...i.files].every(file => {
if (!i.accept) {
return true;
}
return i.accept.replace(/\s/g, '').split(',').filter(accept => {
return new RegExp(accept.replace('*', '.\*')).test(file.type);
}).length > 0;
});
alert('Valid: ' + valid);
}